North Columbia

Low density new snow will continue to accumulate in the coming days.

Moderate - Forecast snowfall amounts are uncertain

FRIDAY: Flurries or periods of snow, accumulation 5 cm overnight Thursday into Friday / Light south southeast wind / Alpine temperature -10 SATURDAY: Flurries, accumulation 5-10cm  / Light southwest wind / Alpine temperature -14 SUNDAY: Mix of sun and cloud / Light southwest wind / Alpine temperature -11

Recent reports show continued observations of wind slabs releasing to Size 1 with skier traffic and ski cutting, primarily on south aspects in the alpine. Additional observations show numerous human triggered and natural loose dry avalanches to size 1 in steep, sheltered terrain. Expect continued potential for triggering loose dry avalanches in steep terrain and consider the potential to trigger persistent slabs as the load continues to increase on top of the mid December persistent weak layer.

10-15cm of low density new snow has buried a recently formed layer of weak feathery surface hoar and/or sugary facets. A layer buried mid-December that consists of surface hoar, sun crust and/or sugary facets is now down approximately 40-60cm.The bond at this old snow interface is of critical importance in areas where the overlying snow has consolidated into a slab. The most concerning areas are those that saw pronounced surface hoar development before the storm, such as sheltered areas at and below treeline, sheltered northerly aspects in the alpine, or anywhere the surface hoar formed on top of a sun crust. Recent snowpack tests show wide ranging reactivity on this weak layer but suggest that it may be most reactive on northerly aspects. A rain crust that formed in late November is now buried 80-110cm deep. Recent reports from the southwest end of this region suggests it may be reactive in steep, variably loaded terrain features in the alpine.